DIVERSITY FOR RESISTANCE TO PUCCINIA-RECONDITA, CAUSING LEAF RUST IN WHEAT (TRITICUM-AESTIVUM)

Diversity for resistance to 7 races of Puccinia recondita Rob. ex Desm., causing leaf rust in wheat (Triticum spp), was studied in 88 strains of bread wheat (Triticum aestivum L emend. Fiori & Paol.), using infection-type matching technique. On the basis of infection type and overall response, these 88 lines were placed in 11 diverse resistance groups, Groups I-XI. Four lines, viz 'NL 459', 'PR 2', '83 SN 9121' and 'RCB 48', showed resistance to races 108, 12, 162 A, 77 and its 3 biotypes 77A, 77-1 and 77-2. Genes Lr1, Lr 3 and Lr 10 were postulated from 38.6, 31.84 and 14.7% of wheat lines respectively. But only 28.4% wheat lines were expected to carry the gene Lr26. During the 3 years of testing, 43 lines showed field resistance, and 50% of these showed adult plant resistance to biotypes 77 A, 77-1 and 77-2 of race 77, indicating race specificity for adult-plant resistance genes.